public class ListAllThreads {

	public static void main(String[] args) {

		new PrintNameThread("A");

		new PrintNameThread("B");

		new PrintNameThread("C");

		ThreadGroup threadGroup = Thread.currentThread().getThreadGroup()
				.getParent();

		Thread[] list = extracted(threadGroup);

		for (Thread thread : list) {
			System.out.println("Thread " + thread + "in the group"
					+ thread.getThreadGroup().getName());
		}

	}

	private static Thread[] extracted(ThreadGroup threadGroup) {
		Thread[] list = new Thread[threadGroup.activeCount()];
		threadGroup.enumerate(list);
		return list;
	}

}
